Method and composition for degreasing skins



Patented'May 1 9.1942

[UNITED STAT'ESaPATENT OFFICE METHOD ND COMPOSITION Fon DEGREASING sxms Fritz-Carl Castendylr, Mattapan, Mass.

No Drawing.

10 Claims.

My invention relates to the removal of natural fats and grease from skins, animal fibers, and other animal raw materials, asin theprocessing of skins or the scouring of wool, being especially skins. The invention, which comprises both the process and novel compositions of matter particularly useful for such skin and fiber treatment, aims to providesubstantialsavingsun the Application January 20, 1939, Serial No. 252,041

adapted for the so-called degreasing" of sheep- 5 time and cost of treatment and to secure an improved product.

By'way of example ,the process will be described with reference to the treatment of sheep- 'skins. These are, received in. the condition" Asapreknown to the trade as pickled skins. liminary step I remove any. remaining flesh from the skins, and preferably dry them to some extent say by removing up to about 30% of their usual moisture content. This drying may be effected by hanging and 'airing the skins, or by use of a centrifuge, or in any other convenient manner. Partially drying the skins it has been found appreciably" facilitates the subsequent treatment of the s kins according to the invention. v

Inthe subsequent treatment of thefleshed partially dried skins they "are conveniently handled in "pac f or batches of approximately 1,000 pounds-such packs each comprising from 300 to 500.01 more -'skins dependingupon their size. The valuesgiven'in the fcllowing descrip tion are thoseappropriate for such packs.

1 A separatedpack of the sheepskins,. fleshed and dried as indicated, is, according to this ex-r;

ample of the invention, placed in a-so-called mill or' tumbling drum in which the internal t amperatu're is desirably from. about to FL,

f that is to'say, substantially ordinary summer temperature.- When colder temperature conditions prevail the drum containing the .batch of skins may be preliminarily heated as by the in- -40 troduction of steam before entering lntoj the' drum thetreating liquornow to be described.

For treating the pack of .skins'a degreasing bath is-supplied the drum. This path conveniently may be prepared in any suitable mixing .45

chamber convenient to the drum is, fol-example,

' a chamber at a higher level than the drum, to 1 which latter? the bath maybe supp ied from the chamber through theusuai hollow drum axle. j ,A 'maioringredient of thebath-sinquantity, 60

is "asuitable substance which will the;

grease, preferably 7 a hydrocarbon got relatively low" volatility.- Preferably this substance is kerosene, 21 to 32. gallons preferablybeing em.- 7

played, 25 gallons ordinarily securing satisfacv 55 of ammonia gas.

.of .the mono-amines, (2) a carrier for this condensation product, and (3) analkalithat will prevent too great an acidity of the liquor during the treating operation.

Preferably the sulphonated condensation prodnot is prepared by subjecting to sulphuric acid a condensation product made by condensing a mixture of mono-ethanol-amine and the fatty acids having 12 to 14 carbon molecules (C1: to C14 acids) naturally occurring in c'ocoanut-oil or other nut oils such as palm nut oil, or mixtures of these oils, This, product maybe made, for example, by taking 210 pounds of cocoanut fatty acids, containing a material quantity of theCm to C14 acids and having an average molecular weight of 210, and heating it with 6'! pounds of mono-ethanoi-amine for a few hours in a still until the acid number determined in alcohol sinks to below 5, the water evolved being allowed toescape. This mass when allowed to cool sets pounds of the subto a wax-like substance. stanoe so prepared may be added to 100 pounds of sulphuric acid monohydrate at from. 30 to 35" :C.' while stirring and cooling. After the mass becomes homogeneous tests may be made to de- 'fniix'ed with ice and neutralized while coolingwith sufllcie'nt50%'. caustic soda to bring the termine the water solubility of the resulting sulphonatedfatty ester, and as soon as the solubility is found to be complete the mass may be whole we neutral reaction to: litmus. Other monomines, such-as mono-propanohamine and monoutyl-amin'e; may be employed, and preftions are made erably in all these'cases the reac with the substances"in the proportion of a single molecule of fatty acid .to singlemolecules of amine and sulphuric acid.

The carrier for the sulphonated fatty ester condensation product above described is preferably suiphonated caster-oil. The alkali is;pret= erabiy a'mmonia, that is to say, a,;water solution A mixture consisting of the for handling. Preferably the minimum amounts mentioned in these ranges are employed. ,The paste or liquid conveniently is stored in closed containers to prevent evaporation of the ammonia gas, and the paste may be diluted with water to make it liquid when it is to be incorporated into the bath. The liquid may be stirred into the kerosene or other liquid hydrocarbon preferably in the chamber above referred to. Preferably the amount so added to the hydrocarbon for a 1,000 pound pack of skins is such as to employ the number of pounds of each substance as just expressed in parts thereof. Preferably the total amount of water in the liquid or bath should be kept at a minimum, and under ordinary conditions should not exceed such amount as will incorporate into the bath about 1 gallon for a 1,000 pound batch of skins.

Other sulphonated water soluble oils, such as sulphonated neats-foot oil, sulphonated cod- 2,283,421 rotated, and rotation of the latter is continued so as to agitate its contents for a periodof about 1.5 to 2.5 hours, at the end of which time or thereabout the natural grease .in the skins will have been liberated, and the liquor in the may be drained ofl. Thereupon the skins in' the 1 lukewarm inwinter and at room temperature or liver oil, sulphonated cotton-seed oil, and, iii

general, any water soluble oil which will act as a carrier for the sulphonated fatty ester and cause it to penetrate the skins, may be employed in place of the sulphonated castor-oil, the latter however it has been found acting particularly satisfactorily as a skin penetrating carrier for the sulphonated fatty ester. Similarly, other water soluble alkalis that will liberate ammonia gas, such as ammonium carbonate, may be employed in place of the ammonia. The amount of alkali employed is such as to prevent too great an acidity of the liquor during the treating operation, which latter it has been found works particularly satisfactorily at an acidity corresponding to a pH value of 2 to 2.5. Ordinarily the amount of ammonia above mentionedwill be sumcient for a 1,000 pound pack .of. ordinary pickled skins. For skins of higher or lower acidity more or less ammonia may be added to the bath to cohtrol the acidity.

In making the above described composition the sulphonated fatty ester preferably is added in powdered form to the sulphonated castor-oil or other carrier to dissolve it therein. The ammonia and preferably such small quantity of water as may be necessary to form a homosomewhat less in summer, may comprise for each washing about 250 gallons of brine solution at about 2 to 6 degrees Baum concentration.

Skins, or other animal product such as wool, so treated are in readiness for further processing and finishing, such as tanning in the case of skins, or carding and the like in the case of wool.

The above described process avcids entirely the necessity" of pressing the material under treatment, such as subjecting it toheavy hydraulic pressure for the purpose of squeezing out which do not resort to pressure but employ commercially known degreasing fluids my process effects a material saving in costs of materials, and may be perforgied in about one-third the time.

It will be understood that, within the scope of the appended claims, de deviations may be made from the form 0 the invention herein described without departing from the spirit of the invention. 1

I claim:

1. The method of degreasing pickled animal skins which comprises drying the skins to remove The temperature at which the skins are treated is of considerable importance and should be excess moisture, and afterward. agitating them with liquid hydrocarbon grease solvent mixed with volatile alkali, water solution of sulphonated oil, and sulphonated product of the condensation reaction of fatty acids containing. a substantial quantity of the C12 and C14 acids with a monoamine, the amount of alkali beingtsuflicient to cause the mixture to have a pH-value of from above 2 to 2.5 when reacting with the skins.

2. The method according to claim 1 in which the mono-amine is mono-ethanol-amine.

3. The method according to claim 1 in which the mono-amine is mono-ethanol-aminejand the fatty acid is the natural occurring fatty acid of cocoanut-oil.

4. The method according to claim 1 in which the alkali is ammonia,'the hydrocarbon is kerosene, and the oil is castor-oil.

the load of skins preferably as the drum is being 76 5. The method according to clairhyl in which a the alkali'is ammonia, the hydrocarbon is keresene, and the oil is castor-oil, the ingredients being in the following proportions with reference to approximately 1,000 pounds of skins: kerosene, 2l.to 32 gallons; ammonia, the equivalent with reference concentration;-

and'sulphonated condensation product, 1.5 to 2.5

'. 6. The method accordingto claim 1 in which is ammonia, the hydrocarbon is kerosene; the oil is caster-oil, the mono-amine is mono-ethanol-amine, and the fatty acid is the natural ocourring'fatty acid of cocoanut-oil. the

ingredients being in the following proportions to approximately 1,000 pounds of skins: kerosene, 21 to 32 gallons; ammonia, the equivalent of 4 sulphonated castor-oil, 5 to 6.5 pounds; and sulphonated condensation product, 1.5to 2.5 pounds.

'LHA composition of matter containing ammonia. water soluble sulphonated castor-oil, and water soluble suiphonated product'of the condensation reactionoi fatty acids containing a to '5 pounds at 26 degrees Baum' which the fatty acid is the natural occurring fatty acid of cocoanut-oil, and the mono-amine is mono-ethanol-amine.

10. A composition of matter containing ammonia, water soluble sulphonatedcastor-oil, water soluble sulphonated product of the condensation reaction of the naturally occurring fatty acids of-cocoanut oil witin'a mono amina and kerosene. in the following proportions: ammonia, 4 to 5 pounds at'26 degrees Baum concentration;

' sulphonated castor-oii; 5 to 6.5 pounds; said substantial quantity of the C12 and C14 acids with ammo-amine, in the following proportions: ammonia, 4 to 5' pounds at 26 degrees Baum con;

condensation reaction product, l.5 to 2.5 pounds;

and kerosene, 21 to 25 gallons.

FRITZ-CARL CASTENDYK.

. 3 centration: sulphonated caster-oil, 5 to 6.5

I cum-12min or canmzfims'. A patent No. 2,235,121. 7 V ma 19, 19!;2. mmycim. c smwm.

It ia hereby certified tint ei-z or eppeara-in the abo ve 'mnioered patent 4 rewiring correction foliage: great, line tit 1e of im rentibgi;

to'r "COflPOSTIOKS,"'-ree.d "COMPOSITIONS- b 'age 2, second eolxmn line :58,v claim 1,- air the werqg'gbove" read -abbut "line 69 70, 1um for "keresene' iead -jker 'se nppage 5 second column, line claim 10, for 1 "ecidg' read acidand this the 5114' Letters Patent ehould. be rm with this con ection th'ereiri that the same confonnto the record of the cue mm Patent orrice.

v Sigied an! sealed tniaaom da br June, 1. n. 19!;2.

I Henry Van Aradnie, (Seal) Acting Cqmmiuioner of Patent 

